Background: Vitiligo has been found to be associated with different HLA antigens in different ethnic groups. In our previous genome-wide association study (GWAS), we identified independent association signal of rs9468925 (P = 2.21 × 10(-33), OR = 0.74) within HLA-C-HLA-B region.
Objectives: To explore the association between rs9468925 polymorphism within MHC and the clinical features of generalized vitiligo.
Methods: The study, using 5566 cases and 6462 controls from previous GWA study investigated the single and combined (GA + GG) genotypic distribution of rs9468925 in subsets of vitiligo patients having different clinical features. We performed a QTL analysis (quantitative trait locus) for age of onset with genotype of rs9468925.
Results: The GA + GG genotypic distribution of SNP rs9468925 tested with an additive model was found to be significantly different in subgroups of patients of >20 vs. <20 years old (genotypic P = 2.57 × 10(-4), combined P = 3.0 × 10(-3), OR = 0.77, 95% CI: 0.64-0.92), and in patients with different clinical subtypes of vitiligo (genotypic P = 0.03, combined P = 5.0 × 10(-3)). However, there was no statistical significance for familial history, halo nevi involvement and autoimmune disease involvement.
Conclusions: Allele G of rs9468925 on HLA-C-HLA-B may be associated with a higher risk of vitiligo. Our study showed a significant genotypic variation between patients with age of onset ≤ 20 years and age of onset >20 years. Obvious clinical differences of generalized vitiligo related to genotypic variation found in the Chinese Han population were confirmed in this study.
© 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.